CEDA DMC Presentation On Dredging Innovations In Gdansk

Group photo of delegates attending the combined meeting of CEDA CEC & DMC and MIG on dredging in Baltic Ports. (Credit: CEDA)

Because of other activities these last weeks, my promised post about the DMC presentation had some delay. On October 10th, there was a symposium together with the Marine Institute Gdansk and the CEDA Environmental Commission and the CEDA Dredging Management Commission supported by Gdansk Science and Technology Park and the Baltic Ports Organisation1. The topic of the symposium was ‘Advances in Dredging Technology. My contribution was a presentation as DMC member2 on ‘Dredging technology developments versus requirements’.

Presenting the innovations in dredging technology. (Credit: CEDA)

Although dredging sounds like an old rusty trade, in fact, it is in constant movement and highly innovative when experienced from the inside. At the Dredging Management Commission, we have a separate focus group, that investigates the technological solutions that enable the stakeholders to efficiently manage a dredging project. A lot of ‘booby traps’ in the ‘Checklist For Successful Dredging Management’3 can be handled by applying the right technology. If there are issues with turbidity, e.g. one can apply a component as the ‘Plumigator®’4 attachment for the overflow in a trailing suction hopper dredge to comply with turbidity clauses in the contract. If the project has very narrow allowances for positioning, modern survey and control systems allow surgical precision dredging, to reduce overdredging and corresponding penalties.

All in all, we’ve identified more than 70 innovation over the last ten years, that have found a foothold in the dredging industry. These have been categorised to the field of technology: Components, Equipment, Industries, Initiatives, Methodology, Processes, Systems, Tools. Other descriptions that we’ve attributed to these innovations were their contribution in solving certain problems in dredging management, as they are found in the checklist. And how much effort they require and how much benefit they would yield. These last items are very subjective and still open for debate. More to follow later. But, at least the procedure can be laid out to recommend the best options for tackling certain problems in the ‘checklist.

Fields of technology and contributions to improvements in dredging management. (Credit: CEDA)

We had a good discussion at the symposium about this topic and from the other focus groups (contract management, checklist, etc.). There were also cross-over opportunities with the CEDA Environmental Commission. At least, there are enough leads, that can be used for the next CEDA Dredging Days in Rotterdam.

As an illustration of the long way we’ve came in the dredging industry, the conference room in the control centre of the Port of Gdansk5, was decorated with interesting pictures from the construction of the port.

Historic pictures of dredging works at the construction of the Port of Gdansk.


  1. CEDA-MIG Joint Symposium on Advances in Dredging Technology 2018 Supported by GSTP and BPO, MIG
  2. Dredging Management Commission, CEDA
  3. New CEDA paper encourages all parties to dredging contracts to start thinking and keep thinking, CEDA
  4. Plumigator, IHC
  5. Port of Gdansk

See also

Celebration: One Year Of Discover Dredging

Celebrating a memorable day with my favourite traditional stroopwaffles

Today is a day to celebrate and I usually celebrate special occasions with traditional Dutch stroopwaffles. It was one year ago, that I introduced my website Discover Dredging to the public1. There was one ‘unofficial’ post before2, but the announcement for the CEDA Dredging Days was seen thousands of times on LinkedIn and served as a grand opening of my own website. Really, it is my own personal stage to tell stories on dredging. I felt the compulsion to share my experience and events with a wider audience. With the blessing of Olivier Marcus, our Director Product Group Dredging, I was encouraged to set up my  website and start telling bits and bobs about the details of dredging.

At the Hydro 2018 conference in Gdansk, Poland, together with Olivier Marcus

It really is in my job description to share knowledge on dredging. Not only for my colleagues, but also for clients, students and general public. For sure the presentations that I have given at conferences are fun to do and are serious projects to execute. But there are so many little things to discover in dredging. My personal website provides me freedom and flexibility to post my own topics at my own pace.

Selection of topics on soil mechanics for dredging (PSD, CPT, SPT, Clay)

Topics I really like, are the ones, where I can explain part of the dredging process in a simple way. The soil mechanics series comes to mind. But dredge pumps and drives are also a favourite topic for me. Often these topics are related to frequently asked questions I receive in my daily job. The posts now offer me a quick reference in case someone asks me the same thing again. I also refer people to my ‘Chapters’ page a lot. From the web site visit metrics, I see this is slowly getting more hits as a landing page.

And as you may have noticed, I am a sucker for ‘old scrap’, sorry: museums. I really like to discover the origins of our modern equipment and see how people in the old days were able to landscape our current world. Other fun things to write about are the current events: ¡VAMOS!, conferences, CEDA, graduations, Damen.

Selection of other dredging topics (Museums, ¡VAMOS!, Graduation Suman Sapkota)

Looking back on one year of writing on Discover Dredging, I can say, that I still enjoy it. And from the responses, you do it too. Reason enough to continue. You can expect a report on a graduation shortly. I have an interesting book recommendation for you. Here in the Netherlands we are going to celebrate Saint Nicholas Day; it will be in time to put it on your wish list. There are still some exhibits from the Damen Dredging Experience to be explained. And there will always be some other topic emerging for publication. Check here regularly or follow me on LinkedIn.

OK, as a small party gift for an anniversary, I still have this colouring page lying around. I used it once in a presentation, but don’t have any specific use for it in a particular topic. I think it is fun enough to share it with you anyway. Have fun!

Colouring page of a dredging equipment toolbox dredge


  1. Countdown to the CEDA Dredging Days 2017
  2. Discover Familiar Grounds in Dredging

See also

HYDRO 2018 Gdansk: Selecting A Dredge For Your Reservoir Maintenance

Barrage du Ksob, M’Sila, Algeria with a DOP dredge 350

This week, I am here in Gdansk for a presentation on the HYDRO 2018 Conference1 and assist at the Damen booth at the corresponding exhibition. The paper and the presentation are already prepared and I am very excited to do the presentation, but I can’t wait till tomorrow and I like to share the story now, already. So, you, as my favourite audience, will have my personal spoiler after so many teasers have been floating around2,3,4.

General modes of siltation at the usual location in a reservoir

The thing is, dam maintenance and reservoir restoration is something already long on my attention list. Back already in 2008, I wrote a paper on this subject for the CEDA Dredging Days5. Over and over we’ve conveyed the message on various platforms, that dredging might be a viable solution for sedimentation problems in reservoirs. Usually, the solution by dam owners and operators is to flush, sluice or store the sediment. This looks horrible from a dredging perspective, but it is also to the environment. You either smother or starve the downstream river with sediment. As a right minded dredge enthusiast, you see many possibilities to dredge such a project. Immediately we can identify what dredge to use on which location for which purpose.

Selection of applicable dredges for reservoir dredging

If you are very close to the dam and the length of the discharge line allows it, you might even not need a dredge pump. (No wear parts!) It is a so called siphon dredge. But as soon as there is some further transport involved, either distance or uphill, you need a dredge like a cutter suction dredge or a DOP dredge. For even further discharge, you might employ a booster for increased discharge pressure. If the distance becomes very far, you might have to resort to grabs and barges.

Water injection dredging principle and example (this example would be too big for a common reservoir)

As an intermediate solution you might even consider using a water injection dredge. Usually the reservoir is in the mountains and a bottom gradient will be present, enabling the required gravity flow. The actual dredge should have created a silt trap where it can collect the inflowing material from the water injection dredge. Than it can handle the material as usual.

Alternative uses for the dredged sediment a) silt farming as fertile additive b) gravel extraction for concrete

Off course, the dredged sediment belongs to the river and the best thing would be to gradually release the sediment after the dam. But there might be conditions, where it is beneficial to extract the valuable fraction of the sediment and use it for agriculture or as aggregate in the construction industry.

Dredge selection diagram for reservoirs

We noticed, that it is often difficult to convey to dam owners and operators which dredge to select for which job. Sediment is seen as a liability and not as an asset and they rather neglect issues associated with the sediment. So, I made an attempt to have a plain and simple selection diagram. That is the core of my manuscript. But my objective is, that we will see many beautiful dredges contributing to a sustainable and viable operation of hydropower dams and reservoirs.

New DOP dredge family


  1. HYDRO 2018: Progress through partnerships, Hydropower and Dams
  2. LinkedIn Teaser, Saskia den Herder
  3. Damen: Spotlight on Hydro Power Dam Maintenance
  4. LinkedIn Teaser, Olivier Marcus
  5. Multi Functional Small Dredging Solution For Maintenance Of Deep Irrigation Reservoirs And Hydro Power Dams, CEDA

See also